Just as our authorities were dealing with the collapse of a 50-year-old structure that killed ten people in north Delhi’s Inderlok on June 28, a similar disaster played out in Chennai.
On the outskirts of the Tamil Nadu capital, 61 persons, mostly contract workers employed at an
under-construction 11-storey building, were buried alive when the structure collapsed. The site where the building was coming up was a huge wetland and the water catchment area for the Porur Lake till a few years ago.

The investigators suspect the soil condition was not favourable for a high-rise.

In Delhi, the Yamuna floodplains and wetlands are home to almost one-fifth of the city’s population. These high-density population areas - from northeast Delhi to Noida, Okhla, Badarpur and Faridabad in Haryana - are highly vulnerable because structures, legal and illegal, have been built on soft alluvial soil. These buildings virtually float on a high groundwater table that keeps weakening their foundations.

What makes it worse is that Delhi’s floodplains are located in seismic zone IV, the second-highest earthquake hazard zone in India. Even medium-intensity tremors can lead to liquefaction of soil — a condition resembling quicksand — sinking all structures resting on water-saturated grounds by the Yamuna.

The bad quality of construction in most unauthorised colonies littering the Yamuna floodplain increases the risk manifold.

Remember the Lalita Park building collapse in 2010 that killed 71 people? The foundation of the wafer-thin structure had simply dissolved in the river water that had accumulated in the basement. No structural audits have ever been done in the unauthorised colonies that earned the legal tag in the run-up to the Delhi Assembly elections last year.

According to a petition in the National Green Tribunal (NGT), nearly 4,000 acre of farmland on the floodplains along 30 km of the river in Noida has been grabbed by the land mafia, mainly to build expensive farmhouses.

Despite the NGT’s order to remove every piece of concrete from the riverbed, the illegal realty market thrives.

The Hindon floodplain in Ghaziabad has also seen unabated construction. In spite of a court moratorium, nothing stops owners from registering these properties with the government.

Construction on riverbed is prohibited only under the rules laid down in the local master plans that are often violated or amended by state governments to suit local interests.

Even if they don’t have vested interest in mind, most governments see their floodplains as wasteland that could be put to use by constructing on it. So Delhi built power plants, metro parking yards, the Secretariat building, Akshardham temple, and most recently the Commonwealth Games Village on the Yamuna riverbed.

Perhaps, it is the government that needs to be policed. But the proposal to notify the River Regulation Zone (RRZ) under the Environment Protection Act of 1986 to regulate both private and public activities on the floodplains has been gathering dust since 2002.

How many Chennai-like tragedies do we need before the risk sinks in?

In many cities across the world, the idea of freeing rivers is gaining ground. In the US, New Orleans is breaking its floodwalls to allow the storm water to come into the city by building new canals and ponds. After building dykes to keep waters from entering the country for 800 years, the Dutch are now implementing the “Room for the River’ project by moving dozens of dykes back, increasing the depth of flood channels, reducing the height of the groynes and constructing a flood bypass.

The Dutch government also demolished 50 houses and some shops to make room for the river Waal. Relocating a fifth of its population is not an option for Delhi.

But as long as authorities keep finding excuses for not removing non-residential structures and upscale farmhouses or imposing a permanent ban on fresh construction in the floodplains, Delhi won’t escape that sinking feeling.